P*****s
发帖数: 375 | 1 Firstly, I'm a biology idiot, so excuse me please..
I know that water affects the DNA's activity. my question is that,
if the DNA, whose activity requires aqueous environment, leaves water
for a while, and later back to water, can it still be active? is there
a time-dependence of such activity with the time DNA leaves water?
Also similar is the problem of temperature. DNA certainly is active when
in room temperature only, but if keep DNA in -20C, and take it out later,
warm it, it still can be a | a***k
发帖数: 27 | 2 I am not sure about the effect of removal from water.
But for the temperature, I THINK the DNA will still be "active". The meaning of a
DNA being active is "it still can serve as template for replication and transcription".
Its being active is always associated with the enzyme RNA polymerase and DNA
polymerase. Low temperature does not denature enzymes (usually in the lab,
enzymes are kept under low temperatures. The temperature of the refridgerator
of my department is -70C. The polymerase e
【在 P*****s 的大作中提到】
: Firstly, I'm a biology idiot, so excuse me please..
: I know that water affects the DNA's activity. my question is that,
: if the DNA, whose activity requires aqueous environment, leaves water
: for a while, and later back to water, can it still be active? is there
: a time-dependence of such activity with the time DNA leaves water?
: Also similar is the problem of temperature. DNA certainly is active when
: in room temperature only, but if keep DNA in -20C, and take it out later,
: warm it, it still can be a
| b***h
发帖数: 26 | 3
go to find a biochemistry book. use the index at the end of the book to find
the chapter on DNA.
【在 P*****s 的大作中提到】
: Firstly, I'm a biology idiot, so excuse me please..
: I know that water affects the DNA's activity. my question is that,
: if the DNA, whose activity requires aqueous environment, leaves water
: for a while, and later back to water, can it still be active? is there
: a time-dependence of such activity with the time DNA leaves water?
: Also similar is the problem of temperature. DNA certainly is active when
: in room temperature only, but if keep DNA in -20C, and take it out later,
: warm it, it still can be a
| p**h
发帖数: 99 | 4
no. one way to store DNA is to dry it.
no. no low temp limit for DNA. DNA can be stored at -70 degree C.
【在 P*****s 的大作中提到】
: Firstly, I'm a biology idiot, so excuse me please..
: I know that water affects the DNA's activity. my question is that,
: if the DNA, whose activity requires aqueous environment, leaves water
: for a while, and later back to water, can it still be active? is there
: a time-dependence of such activity with the time DNA leaves water?
: Also similar is the problem of temperature. DNA certainly is active when
: in room temperature only, but if keep DNA in -20C, and take it out later,
: warm it, it still can be a
| c*****t
发帖数: 1879 | 5
DNA's sole purpose is to surve as a template for replication and
transcription. Itself is chemically stable. Other enzymes/RNAs
read DNA by weak interactions (statics, shape and "hydrophobic
interaction"). Water removal and freezing do not affect the chemical
structure of DNA and therefore do not affect its "activity." Think
DNA as your harddisk.
Just a side note for one of the previous reply post, it is possible
to "cold denature" a protein.
【在 P*****s 的大作中提到】
: Firstly, I'm a biology idiot, so excuse me please..
: I know that water affects the DNA's activity. my question is that,
: if the DNA, whose activity requires aqueous environment, leaves water
: for a while, and later back to water, can it still be active? is there
: a time-dependence of such activity with the time DNA leaves water?
: Also similar is the problem of temperature. DNA certainly is active when
: in room temperature only, but if keep DNA in -20C, and take it out later,
: warm it, it still can be a
| P*****s
发帖数: 375 | 6
I also thought so. DNA is not a very large object, so it shall resume
function on the microscopic level. And you also noted protein -- I
think protein, at least some, of course shall denature, otherwise the
creatures will resume life after expericing very low temperature :))
But which one is the reply post u r noting? And would you please tell
a little more about the "cold denature"? Is denature because of the
change of the chemical structure?
In fact, what I really want to know is about DNA th
【在 c*****t 的大作中提到】
:
: DNA's sole purpose is to surve as a template for replication and
: transcription. Itself is chemically stable. Other enzymes/RNAs
: read DNA by weak interactions (statics, shape and "hydrophobic
: interaction"). Water removal and freezing do not affect the chemical
: structure of DNA and therefore do not affect its "activity." Think
: DNA as your harddisk.
: Just a side note for one of the previous reply post, it is possible
: to "cold denature" a protein.
| s*k
发帖数: 144 | 7
DNA can be large enough that be seen by naked eye.The size is not
principle factor whether a biomolecule will denature or not.
main factor is whether a treatment can destroy biomolecule chemical
and 四级 structure.
Low temperature basically do no harm to cell if the cell is cooled
quick enough to avoide forming large ice crystal that is harmful
to cell membrane.
Many microbes and cells like egg,sperm, and embyro of human and
animals are kept under -70C and can continue their life cycle
under the
【在 P*****s 的大作中提到】
:
: I also thought so. DNA is not a very large object, so it shall resume
: function on the microscopic level. And you also noted protein -- I
: think protein, at least some, of course shall denature, otherwise the
: creatures will resume life after expericing very low temperature :))
: But which one is the reply post u r noting? And would you please tell
: a little more about the "cold denature"? Is denature because of the
: change of the chemical structure?
: In fact, what I really want to know is about DNA th
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